Begin by heating your oven to 350°F. Wrap a 9-inch springform pan securely in a large sheet of foil to keep it protected during baking. Set aside a larger pan filled with water, which will hold the springform pan while it bakes.

In a bowl, combine the graham cracker crumbs, sugar, espresso powder, and melted butter. Mix until the texture resembles damp sand. Press this mixture firmly into the base of the pan, bringing it about 1 inch up the sides to form an even crust.

In a large bowl, blend the cream cheese and ricotta until smooth and well combined. Add the sugar, eggs, lemon juice, vanilla, cornstarch, flour, and butter, mixing until the batter is uniform. Stir in the sour cream last, just until incorporated.

In a separate bowl, stir together the water, espresso powder, and Kahlua until dissolved.

Pour half of the cheesecake filling over the prepared crust and spread it evenly. Dip each ladyfinger briefly into the coffee mixture, then arrange them over the filling, placing them close together in a single layer. Cover with the remaining cheesecake batter, smoothing the top.

Set the pan into the prepared water bath and bake for about 1 hour. When the time is up, turn off the oven and leave the door slightly open to allow the cake to cool gradually for another hour.

Remove the pan from the oven, take off the foil, and let it rest overnight before serving.

Place the mascarpone and powdered sugar in your mixer and beat on medium speed for about a minute, until thick and holding firm peaks. Transfer to a bowl and set aside.

In the same mixer, whip the heavy cream with the vanilla on high speed until soft peaks form. Add the mascarpone mixture back in and beat on medium speed until smooth and creamy, about 1 to 2 minutes.

Spread or pipe the mascarpone whipped cream over the cheesecake and finish with a generous scattering of chocolate shavings before slicing.